A pressure sensor configured such that a pair of interdigtal electrodes and a resistor layer are stacked has been known (for example, Patent Document 1). Such a pressure sensor is configured such that a slight interval is provided between the interdgital electrodes and the resistor layer. At the time of application of a load in the stacking direction of the interdgital electrodes and the resistor layer, as the load increases, the surface area of contact between the interdgital electrodes and the resistor layer increases. With this configuration, an increase in the load applied to the pressure sensor reduces electric resistance between one interdigital electrode and the other interdigital electrode by the amount of the increase in the surface area of contact between the interdigital electrodes and the resistor layer. By reading this change in the electric resistance, pressure applied to the pressure sensor can be measured.